1. Field of the Invention
The present invention relates to an operation method of a washing machine for controlling the rotation of a pulsator to enhance cleaning performance.
2. Description of the Related Art
In general, washing machine refers to an apparatus for removing various contaminants adhered to cleaning objects such as clothes, bedclothes, and the like by a rubbing operation based on the emulsification and rotation of a detergent. The washing machine may be classified into a top load type washing machine in which a tub (or drum) is placed in the vertical direction and a front load type drum washing machine in which a tub (or drum) is placed in the horizontal direction.
Meanwhile, the top load type washing machine may allow cleaning objects to be placed from the top side, and the typical configuration thereof may include a cabinet forming an outer appearance of the washing machine, a tank accommodated in the cabinet to fill washing water, a tub accommodated in the tank to rotate during cleaning or dehydration, a pulsator rotatably provided at a bottom portion of the tub, and a drive portion for concurrently or separately driving the tub and pulsator.
The washing machine initiates the operation by putting cleaning objects and a detergent into the tub. When the operation of the washing machine is initiated, supplying washing water into the tub or tank is initiated, and detergent dissolving and cleaning cycles are initiated. In this case, water flows are formed by the rotation of a pulsator inside the tub or both the tub and pulsator to perform cleaning. Moreover, a dehydration cycle by the rotation of the tub can be carried out, and a drying cycle may be also carried out dependent on the device provided in a washing machine.
In general, the effect of cleaning to clean washing objects may vary based on various factors. Prior to the advent of a washing machine, hand washing may include knocking, rubbing, or kneading of cleaning objects. The means for transferring power to cleaning objects may include the formation of water flows (streams of water) by the rotation of the pulsator.
In other words, if water flows are formed by the rotation of the pulsator, then it may cause rubbing due to a relative speed of cleaning objects against water or rubbing between cleaning objects. Furthermore, the pulsator may be rotated to generate a twist of cleaning objects by water flows. A washing machine may clean cleaning objects by knocking, rubbing, and kneading them using water flows formed by the rotation of the pulsator. Accordingly, cleaning effect may be greatly affected by water flows generated by the rotation of the pulsator.
Meanwhile, a detergent may be put into the washing machine to remove contaminants in cleaning objects through the chemical action of the detergent in order to enhance cleaning effect. In this case, water flows by the rotation of the pulsator or the like may be also formed to uniformly soak the detergent into cleaning objects, thereby dispersing the detergent and changing the position or posture of cleaning objects to increase contact possibility to the detergent. In other words, the rotation of the pulsator may have a great effect on the enhancement of cleaning effect using a detergent.
The formation of water flows performing a key role in the cleaning process is mainly carried out by the rotation of the pulsator. FIG. 1 is a schematic diagram illustrating a rotation pattern of the pulsator in a washing machine in the related art. In case of a typical washing machine in the related art, only forward and reverse rotations may be merely repeated at a predetermined rotation angle (ω0*t0).
However, as described above, since the rotation of the pulsator has a great effect on the cleaning effect, there is a drawback in which a cleaning cycle suitable to cleaning objects made of various materials cannot be implemented by using only simple forward and reverse rotations. Further, there is a drawback in which the maximized cleaning effect on cleaning objects made of various materials cannot be expected.